Process of producing transparent windows in paper, cardboard, and the like



Patented Aug. 10, 1 926.

UNITED STATES ALBERT VEITINGER, OF WURTTEMBERG, GERMANY.

PROCESS or rnonucmo TRANSPARENT wmnows IN IEAPER, CARDBOARD, AND THE.

, LIKE. I

No Drawing. Application filed March 25, 1925. Serial No. 18,318,and in Germany A ruio, 1924.

" sheets of gelatine or the like are first cut to the proper size and shape out of a larger sheet. This method is inconvenient, largely for the reason that the gelatine sheets are liable to curland it is not easy to do the work neatly, with a perfect joint around the window aperture, and comparatively thick films must be used.

According to my invention the glazing I of the Windows is performed in the following Way. A'thin layer of gelatine or other colloidal matter, which will harden to form a solidbut transparent film, is spread upon a slab, say a sheet of glass, and while it is' still soft or viscous the sheet of paper or the like, in which the apertures have been made is spread on it and pressed, rubbed or brushed. without damaging the surface of the colloidal substance exposed by the apertures, over which a suitable cover may be placed. When the colloidal substance has become sufiiciently dry or hard, it is de- 1 tached from the slab, together with the sheet of paper or the like which it covers. This leaves all the Windows glazed byportions of a film whichcovers the whole sheet. D

What I claim as my invention and desire to secure by Letters Patent of the United States is l The process of covering apertures in a sheet with a transparent film, consisting in spreading the sheet on a film of viscous material adapted to adhere thereto and to harden to a solid transparent film, the area of the film being at least equal to the area of the sheet; 4

In' Witness whereof I have signed this specification. y ALBERT VEITINGER. 

